Plate BoundariesBy: Vada Nelson

CONVERGENT BOUNDARIES

Continental - oceanic convergent boundary (subduction)

A convergent boundary (continent - ocean) is created when one continental plate smashes into a oceanic plate and the oceanic plate goes under the continental plate because it's denser, compression stress occurs here. Volcanoes and trenches are land forms that form near convergent boundaries.

Mt. St. Helens

Mt. St. Helens is a volcano in Washington that erupted on May 18, 1980 causing the largest landslide in recorded history and a major volcanic eruption that scattered ash across a dozen states. The volcano, sending shockwaves and pyroclastic flows across the surrounding landscape, flattening forests, melting snow and ice, and generating massive mudflows. A total of 57 people lost their lives in the disaster.

DIVERGENT BOUNDARIES

A Divergent boundary is created when two plates separate and create new oceanic crust, tension stress occurs here. Ridges and volcanoes are landforms that are created by Divergent boundaries.

Volcanoes on Iceland

Katla

Katla is a large volcano in southern Iceland. It is very active; twenty eruptions have been documented between 930 and 1918, at intervals of 13–95 years. Katl's last eruption in 1918. Katla is among the most frequently erupting volcanoes in Iceland, averaging about two eruptions each century. The volcanic massive is partly covered by the glacier Mýrdalsjökull which fills a caldera depression and covers the eruptive vents.

Transform boundaries are places where plates slide sideways past each other. At transform boundaries lithosphere is neither created nor destroyed. Many transform boundaries are found on the sea floor, where they connect segments of diverging mid-ocean ridges. California's San Andreas fault is a transform boundary.

San Andreas Fault

The San Andreas Fault is a continental transform fault that extends roughly 800 miles through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip.On Oct. 17, 1989, the sports world was awaiting the first pitch of Game 3 of the Bay Area World Series between the Oakland Athletics and San Francisco Giants at Candlestick Park Michaels and Tim McCarver were welcoming the TV audience to the park and recapping the previous two games when Michaels announced they were experiencing an earthquake. And it was devastating. The Loma Prieta earthquake — registering at 6.9 on Richter Scale — destroyed bridges and highways, killed more than 60 people and injured thousands of others.